I am thinking of getting a CNC mill, at this stage I am not sure what to look for. I have a bridgeport manual mill and am part way through rebuilding it. I had planned to convert it to CNC but am having second thoughts as it may be smarter to go with a machine designed to be CNC. So please tell me about the bridgeport series 1 and 2 interacts. The reason I am looking at these are:

1. I am guessing it is mechanically similar to the manual series 1. Which I know a little bit about.2. The QC30 spindle means I can keep all my QC30 tooling I have for the manual bridgeport and don't need to buy more, well not straight away. Am I correct to think the QC40 spindles are on the series 2? These might be a bit big for me, but I am open minded.3. I am guessing the weight is in the 1300 Kg area which is about the most I can handle by myself and get in to my home workshop. (Up a nasty path from the road.)4. The size of work it can handle is plenty big enough for me.

I am looking to spend less than £1000. So don't mind a project and I don't mind a full tear down but am hoping not to have to do a full rebuild. I'd like to have an accurate machine when I am done. Does anyone have a link or know of the basic differences across the versions over the years? I'd like to go for a DC servo equipped mill.

Mechanically what goes wrong? Are any of the ways chromed or hardened? I can't scrape hardened or chromed ways so I'll need to know they are in good condition. I've learned that any failed lubrication to a manual bridgeport results in nasty wear.

Regarding controllers, I don't know anything about the different versions, 150, 151, 151B,etc. Any pointerS?

Interacts are extremely solid versatile machines much under rated by many. So long as the controller is AT LEAST a TNC151B then you can drip feed infinitely large programs generated by your favorite CAD/CAM set up, but prior to the 151B you could not drip feed, just load memory up to its max buffer. 151B and onwards it keeps filling the buffer as the machine uses the code, so it can go on for ever.

I hope you find a good one, be picky and don't take the first / cheapest.

I have an Interact 1 Mk2 - and I'd highly recommend it. The Mk2 has a variable speed motor, so it doesn't need the electrically controlled vari-speed head (and therefore doesn't have any double-cone pulley issues); on the other hand, you can't tilt the head, which may (or may not) be a restriction you can/can't live with.

I'd agree with Andrew's comments - the TNC151 controller is the oldest one which supports drip feeding, and since virtually any CAM-produced program will exceed the 999 program steps of the basic controller's memory, so make sure your machine has at least that. I believe the TNC155 will do graphics too.

Also, I'm not sure you'll find one for less than a grand... I paid £1600 for mine, and that was a bit of a bargain. Even so, I've since had to shell out around another £300 in parts to keep it running (blown servo motor), and around another £1000 in preventative spare parts (like a main motor & some more servo motors).

Logged

Cheers!Ade.--Location: Wallasey, Merseyside. A long way from anywhere.Or: Zhengzhou, China. An even longer way from anywhere...Skype: adev73

Thanks Andrew. Nice tip on the 151B. Is there any place with a marking on the machine to 100% confirm a controller is the B variety?

I am open minded on the future and changing controllers. However it would be nice to get a running machine at least until I take it all apart Also I am happy to play a waiting game I just want to know what machine and controller type to be on the look for that fits for me. There seem to be a few mills out there with the TNC2500 controller. The seem to be from £5000 and up which is too much for me. But what are the advantages of the 2500 controller? Also maybe if I need to keep the costs down I need to consider the controller being dead. It seems my budget is too low for a machine with working controller unless I get very very lucky which would be something I am not accustomed to. ;-)

I really know very little about these machines other than what you have taught me and what google is telling me and the fact that the series 1's column and knee are similar to the manual series ones.

Series 2 interact seem to be QC40.Series 1 interact seem to be QC30. MKII seem to have fixed DC drive heads.

Right now I am thinking a Series 1 MKII, which seem to have the fixed DC servo motors head which is fine for me, and now know to look for a 151B controller or later. Or don't worry about the controller and instead think of converting to mach or linuxcnc which in the long term is no problem but in the short term I'd rather get up and running.

I'm not actually sure, but I've got a manual for it somewhere, I'll try to dig it out this week. The chap who brought it to me brought it on his 7.5t lorry, so all I can be sure of is it weighs less than 3.5 metric tons! I'd be surprised if it was much over 1 metric ton though. The DC motor is quite a lot heavier than the regular motor, but can (just!) be lifted by one person, not that I'd like to try fitting it without a crane... the knee & column of the Mk2 are heavier than the manual Bridgeport; the table is shorter & wider, so probably about the same weight overall, especially if your manual has power feeds.

IME, £1600 will buy you a rough but - more or less - working machine; I've had 2, the first one had a bad bearing in the fan that cools the DC motor, and the mist/flood coolant didn't work, also it had the TNC150 controller. The second one, everything works bar the mist coolant (which I don't think is fitted, there's nowhere for the air supply to go), I did have a servo motor go bad which cost several £ in fuses before I figured it out. I got very lucky with mine, the guy selling it on eBay had it finishing at about 2.30am on a Tuesday... so I stayed up to finish the auction... had he finished it at 5pm on a Sunday it'd have gone for at least £1k more.

As far as I am aware, there are 4 variants of the TNC151 controller: A, B, P and Q. I've yet to determine what - if any - differences there are between them. I'm not even sure which one I've got... As far as I know, all of the '151s will accept drip-fed programs. You need a piece of software (readily available from Heidenhain's website) which interfaces between a PC with a serial port & the machine. I run mine on an ancient & nearly dead laptop running Windows XP. The front panel of the machine will tell you (broadly) which controller you have (i.e. 150, 151 or 155), IIRC the 2500 has a different shaped control cabinet (more like a console than a flat panel). I could never get mine to work properly with G-codes. so I just use "Heidenhain Conversational". I use CamBam as my CAM software, someone else had written a TNC155 post-processor which I hacked extensively to work with the TNC151. There's still some bugs in it, but it works OK for my purposes.

Logged

Cheers!Ade.--Location: Wallasey, Merseyside. A long way from anywhere.Or: Zhengzhou, China. An even longer way from anywhere...Skype: adev73

My understanding is that the 151 will accept loading from RS232 but NOT drip feed. 151B onwards does.

You are somewhat correct, 151 series of heidenhan can be delivered in multiple versions. The funny part it is the same system.The B is an option as i understood it that will enable the dripfeed (band tape recorder feed). The same way Siemens do.. The 810M GA3 has several "delivery" features, for one, enabling dripfeed, larger memory capacity and so on.

So usually if you figure out how to adjust the install parts of the PLC in the system it can be unlocked feature.. This would just require alot of google-fu and reading manuals.

In th end tho most of these old systems heidenhan, fanuc and siemens can and prob. should be replaced with LinuxCNC or something. There is alot of features in a modern CNC system you want to get your hands on. I have run my Siemens system for a year now because people kept telling me "why change something that works".. well the thing is, sure it works. But its not userfriendly in any way..

Well after doing some research on the series 1 and series 2 I have come to the conclusion that unless I can find an amazing deal the series 1 MK II is what I am looking for. Reason being the Series 2 is just too heavy for me to deal with. I could well regret that later but for the time being that is my decision.

I have been reading up on the TNC 2500 controllers. So as far as I can tell they are not going to give me much that would hold off a linuxcnc or mach3 conversion compared to a 151B. There do seem to be quite a few Series 1 MK II with TNC2500 controllers for sale. However the asking price is approximately 5 times my budget. Which leads me to the question does anyone have the specification of the DC servo motors for the Series 1 MK II? I need to look at the option of buying a none working or partially working example with the plan for fixing it. Any good sources for affordable replacement modern DC Servos? Same for the ballscrews? and spindle DC servo drive motor?

These are 35A and up to 160V, although you really need a braking module to absorb decel energy. These seem to be pretty good value for money. I just received one this week (they come from Hungary) so it's too soon to comment on their performance. They take a step/dir input and require an encoder on the motor. They look reasonably well made and I'm guessing this is their 4th generation product. The tuning software looks pretty reasonable too.

Used servomotors actually come up fairly frequently on eBay, as I found when I needed one (of course, at the time I actually needed one, there was only one, in the USA, and it cost the thick end of £600 to get it to the UK...). They usually sell for between £200 and £400. If you can wait, the cheaper ones are probably just fine. I've only ever seen one main motor come up, and I bought that.... IIRC it cost £500. Or thereabouts.... I forget now. It's sitting in storage just in case mine ever goes pop.

I'll ask my mate to look out for a machine as well, he's a machine mover by trade, so is often carting lumps of mill or lathe around the country, if he sees a Mk2 being scrapped/sold cheap, I'll get him to let me know & I can pass it on. Unfortunately, he's not a cheap guy to hire, but he is damn good at his job...

Logged

Cheers!Ade.--Location: Wallasey, Merseyside. A long way from anywhere.Or: Zhengzhou, China. An even longer way from anywhere...Skype: adev73

On the Series 1 MK II, it seems so far all of the pictures I can find show that the top of the knees are chromed. Can't scrape chrome.... So it needs to be in reasonable shape. Although a diamond stone and wearing the good parts down to the same level of wear as the worst of it would work.

Are there any other bearing surfaces that are chromed? Top of the saddle?

Also how is the lubrication on these? The manual Series 1 take a lot of wear if the lubrations get blocked. Which they easily do.

Lube oil is supplied from a tank on the back of the machine. It's pumped onto the ways whenever the spindle is running. If it runs out, the machine throws an error - although, weirdly, the error it displays is "loss of 24v supply".... cue much cursing and disassembling/reassembling the 24v supply circuit, before realising it just needed topping up with oil. Don't ask me how I know this, how many times I rebuilt the 24v regulator circuit, or how long the machine was out of commission before I realised what the actual problem was....

I'm fairly sure mine has scraping marks on the saddle ways (not sure about the knee ways), I'll check at the weekend when I'm next down at the workshop (no time during the week).

Logged

Cheers!Ade.--Location: Wallasey, Merseyside. A long way from anywhere.Or: Zhengzhou, China. An even longer way from anywhere...Skype: adev73

I was hoping to get a basic Series 1 MK II for around £1000, however thanks to your kind comments and further research I have decided at that price point I need a contingency budget of at least £1-2k to get the machine up and running. Later on I would be looking at mach3 or linuxcnc. The extra budget would be for new bearings, new (to me) servo motors etc. My primary goal is to get a machine with as little mechanical wear to items and areas I cannot easily fix as possible. Any working controller is a bonus. Plus later I think I would need significantly more to bring it up to par. If I read back what I have just written I would probably be better off saving up and having a budget of £3-5k, but for some strange reason I don't mind a project.

Regarding the "scraping" marks on the ways. Based on pictures of these series 1 MKII's and also my knowledge of how the manual machines were made. I think it is the case that the ways are ground and then bridgeport used their automated biax half moon scraping "NC" machine to break up the ground ways and create oil pockets. This is not a scraped bearing in the traditional sense. And as such they had to do this on the top sides of the bearings as well as the lower side, i.e. the top of the knee is half mooned whereas traditionally it would have simply been scraped and the underside of the saddle would have been the bearing with half moon oil pockets. Also I have learned that because the ways are ground if you do lose lubrication there is enormous "stick slip" and friction and the ways wear excessively.

From what I have seen with this approach broken/missing lubrication has a very very nasty consequence. Normally the chromed ways survive this problem better than the cast iron. So the column, back side of the knee, underside of the saddle, and the underside of the table are all areas that can have very nasty wear. This is not always easy to spot since they are the underside. For example on my manual bridgeport the chromed knee looked as new apart from one short but very deep score but the underside of the saddle was destroyed by stick slip friction welds. Until I took it apart to find the mess I had thought I had a reasonable machine.

Well I just got back from seeing a bridgeport interact 412H, 30 minutes drive from me. Not the machine type that I was originally planning for but it is not much more heavy than a series 2 at 2200Kg and its only a little bit bigger, and I just have enough electrical power for it. .....

The machine is going for less than the series 1 and 2 interacts at the UK dealers google finds. Not much more than my initial budget. It has a BT40 spindle and 12 slot ATC. There was no rust but a pretty nasty filthy cabinet of gunk everywhere.

It has a TNC 355 control. It has been powered off for months. When I powered it on the langauge was German. Initially it complained about being off and then asked for i think the limits to be set. I couldn't get it to traverse the ways or get the spindle running. The table looked pristine, the ways that were exposed look pristine and there was a 3/4 full bijur oiler reservoir and all the oil pipes I could see had oil in them. I had a look inside the spindle and there was no scoring. I did not have access to compressed air but if I go back early next week the seller will have a compressor running.

It had a whole bunch of manuals with it but nothing I could see with the parameters written down. Any ideas what I am looking for?

Unless someone knows what to do and I could get the parameters am I correct to assume the controller is junk. The cabinets were all clean and tidy lots of lights flashing. The main CRT screen was on the blink with the text scrolling up. The seller has it from a bankruptcy and has no idea at all about the controller.

The TNC355 is a good control - basically a TNC155 implemented physically in a different way. I have one controlling my Beaver Partsmaster and it's never missed a beat.

I would not be surprised if the parameters were not in a pocket in the back of the machine - they usually are. If not then the 412 H is not uncommon, you should be able to blag some off another user via the web. Then all you need to set up specifically to your machine, is the exact tool changer location, and the ball screw error and backlash mapping

(Heidenhain in the UK are very helpful, and no doubt your 'in country' Heidenhain people are the same - they should be able to point you to a source)

Back up batteries (3 x Duracell MN1500) need changing every 12 months - it has to be done with the power on - changed mine last week !)

Thanks. I opened up every cabinet looking for the parameters print off. One of the manuals even said where the parameters are stored. No luck.

I have just found a hopefully excellent video on youtube of how to do some simple things on the control:

I'll head back over to see the machine early next week and see if I can get any where. Do you have any idea whereabouts in the different cabinets those 3 x Duracell MN1500 batteries are? I did not see any. I saw a single AA sized battery soldered in to the circuit one of the cabinets.

Ok well I am in negotiation on a fair price for the 412. I am aiming for half my original budget, and if I manage that I'll then be asking for a delivery! Then

I think I'll need 5 times that at least to get it where it needs to be and a fair bit of elbow grease. I'll need to fast track the build of my new "shed" and plan for a much higher ceiling height to get it in.However it has got to be a much better proposition in the longer term than paying silly money on a series 1 or 2 interact. It's only 2200Kg and it will only need to be moved twice and only once by me. The other when they carry my out of my home in a bag or on a stretcher!